Final answer:
The parasitic disease associated with 'fatty' diarrhea is giardiasis, caused by the protozoan Giardia lamblia. Symptoms include greasy stool due to fat malabsorption, and transmission often occurs through contaminated food or water.
Step-by-step explanation:
The parasitic disease associated with "fatty" diarrhea, or greasy stool, is giardiasis. This condition is caused by the flagellated protist Giardia lamblia (also known as Giardia intestinalis or Giardia duodenalis), which attaches to the intestinal mucosa using a large adhesive disk, leading to blocked nutrient absorption including fats. The common symptoms of giardiasis include diarrhea, nausea, stomach cramps, and gas, with greasy stools indicative of the impaired fat absorption.
Giardiasis, often referred to as backpacker's diarrhea or beaver fever, presents symptoms one to three weeks after exposure and can lead to weight loss and possible dehydration. While the parasite remains in the colon, it does not cause systemic infection, and symptoms usually clear within two to six weeks, although chronic infections may occur and can be resistant to treatment.
Diagnosis of giardiasis is made based on presenting signs and symptoms, medical history, and questions regarding recent activities of the patient, as various pathogens can cause similar gastrointestinal issues. Giardiasis is typically transmitted through contaminated food or water following a fecal-oral route.